When a musical instrument manufacturer describes its product's ability to synchronize an arpeggiator or LFOs to external MIDI clock,
it really is almost useless information without further knowledge of the underlying triggering mechanics.

Does it sync to external beat clock? Does it latch into the Master's groove or pattern cycles?

I've created a draft whitepaper for review and seeking fellow GearSlutz's constructive comments to refine the terminology and improve the document.
The goal is to give both keyboardists and synth makers a common language for describing arp/LFO synchronization varieties.

After getting immensely frustrated with the Waldorf Blofeld arp, I began researching the issue. Turns out, after reading other forums, many musicians are getting burned by gear makers claiming proper arp slave sync.

Well done for bringing up a long over due subject. I'm using both an Innerclock Sync Lock (for din+midi clocking) and an Expert Sleepers ES-4 for MIDI note/controller output (and also MIDI clock). What I've noticed, now that my MIDI is sample accurate (excluding chords of course), is that the MIDI devices themselves suffer from poor MIDI implementation, particularly with respect to timing and jitter.

I'll have to read your paper again, as your terminology is new to me. I have a Waldorf Pulse, who's arpeggiator doesn't always work as well as I'd want. Let's say I use a 3 note chord to trigger the Pulse's arpeggiator at the beginning of every 2 bars. Because the MIDI clock message arrives just before the first note of the trigger-chord, the Pulse attempts to play the next note in the arpeggiator sequence (a short annoying blip) and then as soon as the chord is received it immediately starts to re-trigger the arp sequence (stopping the very first note, and hence giving me the sort annoying blip).

Using your terminology, which category of MIDI clock does the Pulse's fall under?

Well done for bringing up a long over due subject. I'm using both an Innerclock Sync Lock (for din+midi clocking) and an Expert Sleepers ES-4 for MIDI note/controller output (and also MIDI clock).

I'll have to read your paper again, as your terminology is new to me. I have a Waldorf Pulse, who's arpeggiator doesn't always work as well as I'd want. Let's say I use a 3 note chord to trigger the Pulse's arpeggiator at the beginning of every 2 bars. Because the MIDI clock message arrives just before the first note of the trigger-chord, the Pulse attempts to play the next note in the arpeggiator sequence (a short annoying blip) and then as soon as the chord is received it immediately starts to re-trigger the arp sequence (stopping the very first note, and hence giving me the sort annoying blip).

Using your terminology, which category of MIDI clock does the Pulse's fall under?

-=+

Thanks.

...that's a new one for me. Might have to add a category 'FUBAR' or something.
But seriously, if I understand what you are describing, it seems like the arp gets into a sort of race condition where it thinks must immediately 'catch up.'
Double triggering; Trying to process two notes at once on the same clock tick. Is that right?
If you happen to have a short audio clip to share, publicly or privately, send me a link and I'll try to dissect it.